Local and national electric building codes require there to be a ground connection between electrical conduits and an enclosure such as a load center or the like. Such codes require this grounding path to be permanent and electrically continuous. Thus, to comply with such requirements, it is common for the installer to employ a secondary ground conductor or wire between these devices rather than rely solely upon the connection to the enclosure.
To satisfy this requirement, many different types of grounding connectors have been designed that secure a ground wire between a load center/enclosure and a metal conduit. Examples of such devices are shown in U.S. Pat. No. 2,974,185, U.S. Pat. No. 3,492,625, U.S. Pat. No. 4,159,859 and U.S. Pat. No. 4,806,108.
The earlier '185 patent shows a grounding bushing having only two locations at which a ground wire connection can be made. This can be problematic if either of these two ground wire connecting locations end up being inaccessible due to the limited space within the load center/enclosure. The '625 patent improves upon this earlier patent by providing a grounding bushing having three such locations where a ground wire can be secured thereto. The '108 patent improves upon these former patents even further by providing a multitude of different locations where the ground wire connection can occur. The '859 patent is unique in that not only does it show a multitude of different locations where the ground wire can be attached to the grounding bushing, but this patent also discloses a separate cable connector member 12 that can be rotated about its connection to the grounding bushing. This provides even more options for the installer to make the ground wire connection within the tight confines of the enclosure.
U.S. Pat. No. 3,967,872 varies from the above in that a cradle type grounding lug is secured between or intermediate adjacent projections 18 rather than at these projection locations themselves as would be done according to the earlier cited patents.
The number and location of ground wire connections is very important to the installer since the more ground wire connection points available, the less need there is for the installer to manipulate the bushing so as to make a connection point accessible. In the past, it was common for an installer to either un-tighten or over-tighten the bushing within the enclosure in order to align or get access to the connection point for the ground wire. Thus, it frequently occurred that an installer secured a ground wire to the connector, but the connector was not properly secured to the enclosure or the conduit. This, of course, is to be avoided at all costs!
It should also be noted that, as shown in the above identified patents, it is quite common to require the installer to insert the ground wire into a separate clip, lug or device and then require the installer to turn a screw so as to secure the ground wire within the clip. Hence, in these types of situation, two potentially limiting issues must be overcome by the installer. First, the screw must be accessible and at such an angle so that it can be torqued as needed against the ground wire. In the tight confines of an electrical enclosure, it is more often the case that such accessibility is not possible and hence to make it accessible, the conduit connector must be compromised such as by being loosened. Second, the separate clip can be readily lost or it can project so far as to interfere with an adjacent connector such that the clip cannot be employed. Unfortunately, these issues do not surface until the connector is actually installed as it is not possible to know beforehand whether there will be a conflict or not. Thus, there always exists the possibility when using these types of clip ground wire connectors, that the situation at the installation site is such that the connector cannot be employed, or if employed, will not be installed as specified by the manufacturer.
Further still, it is to be noted that many existing ground connectors are manufactured by casting. This is a costly and time-consuming manufacturing method and one that does not readily lend itself to streamlining or to large volumes. Thus, a simpler and quicker way to manufacture ground wire connectors is desirable.
There is therefore a need to be able to install a ground wire connector without regard to the final position or location of the ground wire connector component. It is also desired to be able to install the connector without incurring any interference with adjacent connectors. Yet another desirable feature is to be able to install the connector as tight as needed knowing that there is no potential need to ‘back-off’ or over-tighten the connector in order to properly align the connector with the ground wire. Still another desirable feature is to be able to install the connector without being concerned whether access to the ground wire component will be blocked or not. A further desire is to employ a connector that can be readily installed with a minimum number of parts so as to streamline the assembly and reduce the possibility of lost or dropped components. Yet another desirable feature is to be assured of a permanent and electrically continuous ground path between the conduit and the enclosure. Still another desirable feature is to be able to manufacture such a connector in a cost effective manner that readily lends itself to high volumes. These and other objects and advantages of this invention will be described in greater detail below.